The present invention relates to closures for containers and more particularly to tear tab closures for bottles and the like for containing fluid under pressure.
For a tear tab closure to be practical, it is essential that the tear tab be capable of being gripped easily but securely by the finger of the user and manipulated to open the closure effectively under unfavorable conditions with minimum risk of injury to the user. In the past, attempts have been made to achieve these objectives by using a relatively long tear tab provided with parallel embossings in the form of pyramids, ridges, or the like disposed perpendicularly to the tearing direction, as shown in prior U.S. Pat. Nos. 1,052,382 to Schmitt and 2,068,444 to Breckenridge.
It is often difficult for such tabs to be gripped and manipulated properly even by a person of normal motor ability and muscle strength. Also, under unfavorable conditions, as where the finger of the user or the tear tab is wet, there is risk of injury in the event the fingers of the user slip. Moreover, it is possible for the tear strip to be torn open accidentally if the tab projects from the container and catches against the edge of a table or the like.
It has also been proposed to use caps having a tear tab terminating in an integral circular ring adapted to receive a finger of the user, as illustrated in prior U.S. Pat. Nos. 3,380,609 to Potts, 3,785,519 to Huh, and 3,974,931 to Moller. These caps, however, are very difficult to make and therefore very expensive. Moreover, both they and caps having long tear tabs require complicated machinery in their manufacture.